The present invention relates to a mounting structure for cutters for a rotary tilling device having a rotary cutting device.
The rotary cutters in the rotary cutting device rotate downwardly or upwardly in the soil to break up the surface soil. The conventional rotary tilling device is used for only cultivating the soil and is not contructed to perform other work such as mowing.
The applicant proposed a rotary tilling device which is also used for mowing by a rotary cutter device in the opposite direction. In the rotary tilling device, each cutter is rotatably mounted on a pivotal member such as a bolt secured to a supporting member and held at an angular position by a stopper when tilling.
However, in such rotary tilling device, a lateral gap is provided between the cutter and fastening means in order to allow it to rotate about the bolt. Accordingly, load exerted on the cutter during tilling operation causes shifting thereof in the lateral direction of the tilling device (in the axial direction of the bolt). The continuous lateral shifting or reciprocating of the cutter decreases the workability of the device. Further, since the cutter is rotatable about the bolt in the opposite direction when tilling, the cutter may swing during operation, which causes unstable tilling operation.